Line edge roughness reduction via step size alteration

ABSTRACT

An image correction application relating to the ability to apply maskless lithography patterns to a substrate in a manufacturing process is disclosed. The embodiments described herein relate to a software application platform, which corrects non-uniform image patterns on a substrate. The application platform method includes in a digital micromirror device (DMD) installed in an image projection system, the DMD having a plurality of columns, each column having a plurality of mirrors, disabling at least one entire column of the plurality of columns, exposing a first portion of the substrate to a first shot of electromagnetic radiation, exposing a second portion of the substrate to a second shot of electromagnetic radiation, and iteratively translating the substrate a step size and exposing another portion of the substrate to another shot of electromagnetic radiation until the substrate has been completely exposed to shots of electromagnetic radiation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application Ser.No. 62/214,793, filed Sep. 4, 2015, which is hereby incorporated byreference in its entirety.

BACKGROUND

Field

Embodiments of the present disclosure generally relate to the field ofmaskless lithography. More specifically, embodiments provided hereinrelate to a system and method for performing maskless digitallithography manufacturing processes.

Description of the Related Art

Photolithography is widely used in the manufacturing of semiconductordevices and display devices, such as liquid crystal displays (LCDs).Large area substrates are often utilized in the manufacture of LCDs.LCDs, or flat panels, are commonly used for active matrix displays, suchas computers, touch panel devices, personal digital assistants (PDAs),cell phones, television monitors, and the like. Generally, flat panelsmay include a layer of liquid crystal material forming pixels sandwichedbetween two plates. When power from the power supply is applied acrossthe liquid crystal material, an amount of light passing through theliquid crystal material may be controlled at pixel locations enablingimages to be generated.

Microlithography techniques are generally employed to create electricalfeatures incorporated as part of the liquid crystal material layerforming the pixels. According to this technique, a light-sensitivephotoresist is typically applied to at least one surface of thesubstrate. Then, a pattern generator exposes selected areas of thelight-sensitive photoresist as part of a pattern with light to causechemical changes to the photoresist in the selective areas to preparethese selective areas for subsequent material removal and/or materialaddition processes to create the electrical features.

In order to continue to provide display devices and other devices toconsumers at the prices demanded by consumers, new apparatuses,approaches, and systems are needed to precisely and cost-effectivelycreate patterns on substrates, such as large area substrates.

As the foregoing illustrates, there is a need for an improved techniquefor correcting non-uniform patterns. More specifically, what is neededin the art is an application that manipulates columns of mirrors in thepattern generator to reduce line edge roughness.

SUMMARY

An image correction application relating to the ability to applymaskless lithography patterns to a substrate in a manufacturing processis disclosed. The embodiments described herein relate to a softwareapplication platform, which corrects non-uniform image patterns on asubstrate.

In one embodiment, a method for correcting non-uniform image patterns ona substrate is disclosed. The method may include in a digitalmicromirror device (DMD) installed in an image projection system, theDMD having a plurality of columns, each column having a plurality ofmirrors, disabling at least one entire column of the plurality ofcolumns, exposing a first portion of the substrate to a first shot ofelectromagnetic radiation, translating the substrate a step size andexposing a second portion of the substrate to a second shot ofelectromagnetic radiation, and iteratively translating the substrate astep size and exposing another portion of the substrate to another shotof electromagnetic radiation until the substrate has been completelyexposed to shots of electromagnetic radiation.

In another embodiment, a computer system for correcting non-uniformimage patterns on a substrate is disclosed. The computer system mayinclude a processor and a memory storing instructions that, whenexecuted by the processor, cause the computer system to, in a digitalmicromirror device (DMD) installed in an image projection system, theDMD having a plurality of columns, each column having a plurality ofmirrors, disable at least one entire column of the plurality of columns,expose a first portion of the substrate to a first shot ofelectromagnetic radiation, translate the substrate a step size andexpose a second portion of the substrate to a second shot ofelectromagnetic radiation, and iteratively translate the substrate astep size and expose another portion of the substrate to another shot ofelectromagnetic radiation until the substrate has been completelyexposed to shots of electromagnetic radiation.

In yet another embodiment, a non-transitory computer-readable storagemedium, storing instructions that, when executed by a processor, cause acomputer system to correct non-uniform image patterns on a substrate isdisclosed. The processor may perform the steps of in a digitalmicromirror device (DMD) installed in an image projection system, theDMD having a plurality of columns, each column having a plurality ofmirrors, disabling at least one entire column of the plurality ofcolumns, exposing a first portion of the substrate to a first shot ofelectromagnetic radiation, translating the substrate a step size andexposing a second portion of the substrate to a second shot ofelectromagnetic radiation, and iteratively translating the substrate astep size and exposing another portion of the substrate to another shotof electromagnetic radiation until the substrate has been completelyexposed to shots of electromagnetic radiation.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlyexemplary embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may be applied toother equally effective embodiments.

FIG. 1 is a perspective view of a system that may benefit fromembodiments disclosed herein.

FIG. 2 is a cross-sectional side view of the system of FIG. 1 accordingto one embodiment.

FIG. 3 is a perspective schematic view of a plurality of imageprojection systems according to one embodiment.

FIG. 4 is a perspective schematic view of an image projection system ofthe plurality of image projection devices of FIG. 3 according to oneembodiment.

FIG. 5 schematically illustrates a beam being reflected by two mirrorsof the DMD according to one embodiment.

FIG. 6 illustrates a computer system for providing correction ofnon-uniform image patterns according to one embodiment.

FIG. 7 illustrates a more detailed view of a server of FIG. 6 accordingto one embodiment.

FIG. 8 illustrates a controller computing system used to access anon-uniform pattern correction application according to one embodiment.

FIG. 9 illustrates a method of correcting non-uniform image patterns ona substrate.

FIG. 10 illustrates a DMD having a plurality of mirrors according to oneembodiment.

FIG. 11 illustrates areas of the substrate that are exposed to a firstshot of electromagnetic radiation.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments of the disclosure generally relate to a software applicationrelating to the ability to apply maskless lithography patterns to asubstrate in a manufacturing process is disclosed. The softwareapplication includes disabling at least one entire column of mirrors ina digital micromirror device (DMD) installed in an image projectionsystem, wherein the DMD has a plurality of columns, each column having aplurality of mirrors, exposing a first portion of the substrate to afirst shot of electromagnetic radiation, exposing a second portion ofthe substrate to a second shot of electromagnetic radiation, andrepeating exposing a second portion of the substrate to a second shotuntil the substrate is fully processed.

The term “user” as used herein includes, for example, a person or entitythat owns a computing device or wireless device; a person or entity thatoperates or utilizes a computing device or a wireless device; or aperson or entity that is otherwise associated with a computing device ora wireless device. It is contemplated that the term “user” is notintended to be limiting and may include various examples beyond thosedescribed.

FIG. 1 is a perspective view of a system 100 that may benefit fromembodiments disclosed herein. The system 100 includes a base frame 110,a slab 120, two or more stages 130, and a processing apparatus 160. Thebase frame 110 may rest on the floor of a fabrication facility and maysupport the slab 120. Passive air isolators 112 may be positionedbetween the base frame 110 and the slab 120. The slab 120 may be amonolithic piece of granite, and the two or more stages 130 may bedisposed on the slab 120. A substrate 140 may be supported by each ofthe two or more stages 130. A plurality of holes (not shown) may beformed in the stage 130 for allowing a plurality of lift pins (notshown) to extend therethrough. The lift pins may rise to an extendedposition to receive the substrate 140, such as from a transfer robot(not shown). The transfer robot may position the substrate 140 on thelift pins, and the lift pins may thereafter gently lower the substrate140 onto the stage 130.

The substrate 140 may, for example, be made of quartz and be used aspart of a flat panel display. In other embodiments, the substrate 140may be made of other materials such as glass. In some embodiments, thesubstrate 140 may have a photoresist layer formed thereon. A photoresistis sensitive to radiation and may be a positive photoresist or anegative photoresist, meaning that portions of the photoresist exposedto radiation will be respectively soluble or insoluble to a photoresistdeveloper applied to the photoresist after the pattern is written intothe photoresist. The chemical composition of the photoresist determineswhether the photoresist will be a positive photoresist or negativephotoresist. For example, the photoresist may include at least one ofdiazonaphthoquinone, a phenol formaldehyde resin, poly(methylmethacrylate), poly(methyl glutarimide), and SU-8. In this manner, thepattern may be created on a surface of the substrate 140 to form theelectronic circuitry.

The system 100 may further include a pair of supports 122 and a pair oftracks 124. The pair of supports 122 may be disposed on the slab 120,and the slab 120 and the pair of supports 122 may be a single piece ofmaterial. The pair of tracks 124 may be supported by the pair of thesupports 122, and the two or more stages 130 may move along the tracks124 in the X-direction. In one embodiment, the pair of tracks 124 is apair of parallel magnetic channels. As shown, each track 124 of the pairof tracks 124 is linear. In other embodiments, the track 124 may have anon-linear shape. An encoder 126 may be coupled to each stage 130 inorder to provide location information to a controller 602 (See FIG. 8).

The processing apparatus 160 may include a support 162 and a processingunit 164. The support 162 may be disposed on the slab 120 and mayinclude an opening 166 for the two or more stages 130 to pass under theprocessing unit 164. The processing unit 164 may be supported by thesupport 162. In one embodiment, the processing unit 164 is a patterngenerator configured to expose a photoresist in a photolithographyprocess. In some embodiments, the pattern generator may be configured toperform a maskless lithography process. The processing unit 164 mayinclude a plurality of image projection systems (shown in FIG. 3)disposed in a case 165. The processing apparatus 160 may be utilized toperform maskless direct patterning. During operation, one of the two ormore stages 130 moves in the X-direction from a loading position, asshown in FIG. 1, to a processing position. The processing position mayrefer to one or more positions of the stage 130 as the stage 130 passesunder the processing unit 164. During operation, the two or more stages130 may be lifted by a plurality of air bearings 202 (shown in FIG. 2)and may move along the pair of tracks 124 from the loading position tothe processing position. A plurality of vertical guide air bearings (notshown) may be coupled to each stage 130 and positioned adjacent an innerwall 128 of each support 122 in order to stabilize the movement of thestage 130. Each of the two or more stages 130 may also move in theY-direction by moving along a track 150 for processing and/or indexingthe substrate 140.

FIG. 2 is a cross-sectional side view of the system 100 of FIG. 1according to one embodiment. As shown, each stage 130 includes aplurality of air bearings 202 for lifting the stage 130. Each stage 130may also include a motor coil (not shown) for moving the stage 130 alongthe tracks 124. The two or more stages 130 and the processing apparatus160 may be enclosed by an enclosure (not shown) in order to providetemperature and pressure control.

FIG. 3 is a perspective schematic view of a plurality of imageprojection systems 301 according to one embodiment. As shown in FIG. 3,each image projection system 301 produces a plurality of write beams 302onto a surface 304 of the substrate 140. As the substrate 140 moves inthe X-direction and Y-direction, the entire surface 304 may be patternedby the write beams 302. The number of the image projection systems 301may vary based on the size of the substrate 140 and/or the speed ofstage 130. In one embodiment, there are 22 image projection systems 164in the processing apparatus 160.

FIG. 4 is a perspective schematic view of one image projection system301 of the plurality of image projection systems 301 of FIG. 3 accordingto one embodiment. The image projection system 301 may include a lightsource 402, an aperture 404, a lens 406, a mirror 408, a digitalmicromirror device (DMD) 410, a light dump 412, a camera 414, and aprojection lens 416. The light source 402 may be a light emitting diode(LED) or a laser, and the light source 402 may be capable of producing alight having predetermined wavelength. In one embodiment, thepredetermined wavelength is in the blue or near ultraviolet (UV) range,such as less than about 450 nm. The mirror 408 may be a sphericalmirror. The projection lens 416 may be a 10× objective lens. The DMD 410may include a plurality of mirrors, and the number of mirrors maycorrespond to the resolution of the projected image. In one embodiment,the DMD 410 includes 1920×1080 mirrors, which represent the number ofpixels of a high definition television or other flat panel displays.

During operation, a beam 403 having a predetermined wavelength, such asa wavelength in the blue range, is produced by the light source 402. Thebeam 403 is reflected to the DMD 410 by the mirror 408. The DMD 410includes a plurality of mirrors that may be controlled individually, andeach mirror of the plurality of mirrors of the DMD 410 may be at “on”position or “off” position, based on the mask data provided to the DMD410 by the controller (not shown). When the beam 403 reaches the mirrorsof the DMD 410, the mirrors that are at “on” position reflect the beam403, i.e., forming the plurality of write beams 302, to the projectionlens 416. The projection lens 416 then projects the write beams 302 tothe surface 304 of the substrate 140. The mirrors that are at “off”position reflect the beam 403 to the light dump 412 instead of thesurface 304 of the substrate 140.

FIG. 5 illustrates two mirrors 502, 504 of the DMD 410 according to oneembodiment. As shown, each mirror 502, 504 of the DMD 410 is disposed ona tilting mechanism 506, which is disposed on a memory cell 508. Thememory cell 508 may be a CMOS SRAM. During operation, each mirror 502,504 is controlled by loading the mask data into the memory cell. Themask data electrostatically controls the tilting of the mirror 502, 504in a binary fashion. When the mirror 502, 504 is in a reset mode orwithout power applied, it may be set to a flat position, notcorresponding to any binary number. Zero in binary may correspond to an“off” position, which means the mirror is tilted at −10 degrees, −12degrees, or any other feasibly negative tilting degree. One in binarymay correspond to an “on” position, which means the mirror is tilted at+10 degrees, +12 degrees, or any other feasibly positive tilting degree.As shown in FIG. 5, the mirror 502 is at “off” position and the mirror504 is at “on” position.

The beam 403 may be reflected by the two mirrors 502, 504 of the DMD410, according to one embodiment. As shown, the mirror 502, which is at“off” position, reflects the beam 403 generated from the light source402 to the light dump 412. The mirror 504, which is at “on” position,forms the write beam 302 by reflecting the beam 403 to the projectionlens 416.

FIG. 6 illustrates a computing system 600 configured for correctingnon-uniform image patterns on a substrate in which embodiments of thedisclosure may be practiced. As shown, the computing system 600 mayinclude a plurality of servers 608, a non-uniform pattern correctionapplication 612, and a plurality of controllers (i.e., computers,personal computers, mobile/wireless devices) 602 (only two of which areshown for clarity), each connected to a communications network 606 (forexample, the Internet). The servers 608 may communicate with thedatabase 614 via a local connection (for example, a Storage Area Network(SAN) or Network Attached Storage (NAS)) or over the Internet. Theservers 608 are configured to either directly access data included inthe database 614 or to interface with a database manager that isconfigured to manage data included within the database 614.

Each controller 602 may include conventional components of a computingdevice, for example, a processor, system memory, a hard disk drive, abattery, input devices such as a mouse and a keyboard, and/or outputdevices such as a monitor or graphical user interface, and/or acombination input/output device such as a touchscreen which not onlyreceives input but also displays output. Each server 608 and thenon-uniform pattern correction application 612 may include a processorand a system memory (not shown), and may be configured to manage contentstored in database 614 using, for example, relational database softwareand/or a file system. The servers 608 may be programmed to communicatewith one another, the controllers 602, and the non-uniform patterncorrection application 612 using a network protocol such as, forexample, the TCP/IP protocol. The non-uniform pattern correctionapplication 612 may communicate directly with the controllers 602through the communications network 606. The controllers 602 areprogrammed to execute software 604, such as programs and/or othersoftware applications, and access applications managed by servers 608.

In the embodiments described below, users may respectively operate thecontrollers 602 that may be connected to the servers 608 over thecommunications network 606. Pages, images, data, documents, and the likemay be displayed to a user via the controllers 602. Information andimages may be displayed through a display device and/or a graphical userinterface in communication with the controller 602.

It is noted that the controller 602 may be a personal computer, laptopmobile computing device, smart phone, video game console, home digitalmedia player, network-connected television, set top box, and/or othercomputing devices having components suitable for communicating with thecommunications network 606 and/or the required applications or software.The controller 602 may also execute other software applicationsconfigured to receive content and information from the non-uniformpattern correction application 612.

FIG. 7 illustrates a more detailed view of the non-uniform patterncorrection application 612 of FIG. 6. The non-uniform pattern correctionapplication 612 includes, without limitation, a central processing unit(CPU) 702, a network interface 704, memory 720, and storage 730communicating via an interconnect 706. The non-uniform patterncorrection application 612 may also include I/O device interfaces 708connecting I/O devices 710 (for example, keyboard, video, mouse, audio,touchscreen, etc.). The non-uniform pattern correction application 612may further include the network interface 804 configured to transmitdata via the communications network 606.

The CPU 702 retrieves and executes programming instructions stored inthe memory 720 and generally controls and coordinates operations ofother system components. Similarly, the CPU 702 stores and retrievesapplication data residing in the memory 720. The CPU 702 is included tobe representative of a single CPU, multiple CPU's, a single CPU havingmultiple processing cores, and the like. The interconnect 706 is used totransmit programming instructions and application data between the CPU702, I/O device interfaces 708, storage 730, network interfaces 704, andmemory 720.

The memory 720 is generally included to be representative of a randomaccess memory and, in operation, stores software applications and datafor use by the CPU 702. Although shown as a single unit, the storage 730may be a combination of fixed and/or removable storage devices, such asfixed disk drives, floppy disk drives, hard disk drives, flash memorystorage drives, tape drives, removable memory cards, CD-ROM, DVD-ROM,Blu-Ray, HD-DVD, optical storage, network attached storage (NAS), cloudstorage, or a storage area-network (SAN) configured to storenon-volatile data.

The memory 720 may store instructions and logic for executing anapplication platform 726 which may include non-uniform patterncorrection application software 728. The storage 730 may include adatabase 732 configured to store data 734 and associated applicationplatform content 736. The database 732 may be any type of storagedevice.

Network computers are another type of computer system that can be usedin conjunction with the disclosures provided herein. Network computersdo not usually include a hard disk or other mass storage, and theexecutable programs are loaded from a network connection into the memory720 for execution by the CPU 802. A typical computer system will usuallyinclude at least a processor, memory, and an interconnect coupling thememory to the processor.

FIG. 8 illustrates a controller 602 used to access the non-uniformpattern correction application 612 and retrieve or display dataassociated with the application platform 726. The controller 602 mayinclude, without limitation, a central processing unit (CPU) 802, anetwork interface 804, an interconnect 806, a memory 820, storage 830,and support circuits 840. The controller 602 may also include an I/Odevice interface 808 connecting I/O devices 810 (for example, keyboard,display, touchscreen, and mouse devices) to the controller 602.

Like CPU 702, CPU 802 is included to be representative of a single CPU,multiple CPU's, a single CPU having multiple processing cores, etc., andthe memory 820 is generally included to be representative of a randomaccess memory. The interconnect 806 may be used to transmit programminginstructions and application data between the CPU 802, I/O deviceinterfaces 808, storage 830, network interface 804, and memory 820. Thenetwork interface 804 may be configured to transmit data via thecommunications network 606, for example, to transfer content from thenon-uniform pattern correction application 612. Storage 830, such as ahard disk drive or solid-state storage drive (SSD), may storenon-volatile data. The storage 830 may contain a database 831. Thedatabase 831 may contain data 832, other content 834, and an imageprocess unit 836 having data 838 and control logic 839. Illustratively,the memory 820 may include an application interface 822, which itselfmay display software instructions 824, and/or store or display data 826.The application interface 822 may provide one or more softwareapplications which allow the controller to access data and other contenthosted by the non-uniform pattern correction application 612.

As shown in FIG. 8, the system 100 includes a controller 602. Thecontroller 602 is generally designed to facilitate the control andautomation of the processing techniques described herein. The controller602 may be coupled to or in communication with one or more of theprocessing apparatus 160, the stages 130, and the encoder 126. Theprocessing apparatus 160 and the stages 130 may provide information tothe controller 602 regarding the substrate processing and the substratealigning. For example, the processing apparatus 160 may provideinformation to the controller 602 to alert the controller that substrateprocessing has been completed. The encoder 126 may provide locationinformation to the controller 602, and the location information is thenused to control the stages 130 and the processing apparatus 160.

The controller 602 may include a central processing unit (CPU) 802,memory 820, and support circuits 840 (or I/O 808). The CPU 802 may beone of any form of computer processors that are used in industrialsettings for controlling various processes and hardware (e.g., patterngenerators, motors, and other hardware) and monitor the processes (e.g.,processing time and substrate position). The memory 820, as shown inFIG. 8, is connected to the CPU 802, and may be one or more of a readilyavailable memory, such as random access memory (RAM), read only memory(ROM), floppy disk, hard disk, or any other form of digital storage,local or remote. Software instructions and data can be coded and storedwithin the memory for instructing the CPU 802. The support circuits 840are also connected to the CPU 802 for supporting the processor in aconventional manner. The support circuits 840 may include conventionalcache 842, power supplies 844, clock circuits 846, input/outputcircuitry 848, subsystems 850, and the like. A program (or computerinstructions) readable by the controller 602 determines which tasks areperformable on a substrate. The program may be software readable by thecontroller 602 and may include code to monitor and control, for example,the processing time and substrate position.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the following discussion,it is appreciated that throughout the description, discussions utilizingterms such as “processing” or “computing” or “calculating” or“determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical(electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission, or display devices.

The present example also relates to an apparatus for performing theoperations herein. This apparatus may be specially constructed for therequired purposes, or it may comprise a general purpose computerselectively activated or reconfigured by a computer program stored inthe computer. Such a computer program may be stored in a computerreadable storage medium, such as, but is not limited to, read-onlymemories (ROMs), random access memories (RAMs), EPROMs, EEPROMs, flashmemory, magnetic or optical cards, any type of disk including floppydisks, optical disks, CD-ROMs, and magnetic-optical disks, or any typeof media suitable for storing electronic instructions, and each coupledto a computer system interconnect.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct a more specializedapparatus to perform the required method operations. The structure for avariety of these systems will appear from the description above. Inaddition, the present examples are not described with reference to anyparticular programming language, and various examples may thus beimplemented using a variety of programming languages.

As described in greater detail within, embodiments of the disclosurerelate to an image correction application relating to the ability toapply maskless lithography patterns to a substrate in a manufacturingprocess is disclosed. The embodiments described herein relate to asoftware application platform, which corrects non-uniform image patternson a substrate. The application platform method includes disabling atleast one entire column of mirrors in the DMD, wherein the DMD has aplurality of columns each column having a plurality of mirrors, exposinga first portion of the substrate to a first shot of electromagneticradiation, exposing a second portion of the substrate to a second shotof electromagnetic radiation, and repeating exposing a second portion ofthe substrate to a second shot of electromagnetic radiation until thesubstrate is fully processed.

FIG. 9 illustrates a method 990 of correcting non-uniform image patternson a substrate. The method may be performed by a controller 602, asshown in FIG. 8. The method 990 begins at block 992. At block 992, thecontroller disables at least one entire column of mirrors in the DMD,wherein the DMD has a plurality of columns, each column having aplurality of mirrors. In one embodiment the controller disables at leastone entire column of mirrors in the DMD based on measuring a measuredangle of rotation of the DMD. When the DMD is installed in the imageprojection system, the DMD may be installed at some angle. The angle ofinstallation may result in an interference pattern on the substrate. Toreduce the interference pattern on the substrate, at least one entirecolumn of mirrors in the DMD is disabled. In one embodiment, the atleast one entire column of mirrors in the DMD is disabled responsive tomeasuring an angle of rotation of a DMD installed in the imageprojection system.

Referring to FIG. 10, FIG. 10 illustrates a DMD 1000 having a pluralityof mirrors 1024. The plurality of mirrors 1024 are arranged in a gridhaving M rows and N columns. In FIG. 10, rows 1001, 1002, 1004, 1006,1008, 1010, and columns 1012, 1014, 1016, 1018, 1020, and 1022 areshown. A controller determines how many columns or rows of mirrors 1024to disable. In one embodiment, the controller determines how manycolumns or rows of mirrors 1024 to disable in response to measuring theangle of rotation of the DMD 1000 installed in the image projectionsystem. The controller refers to a table (not shown) in which the usermay enter the DMD's 1000 angle of rotation and number or shots desiredto output the number of columns or rows that should be disabled. Thecontroller then disables the correct number of columns or rows. Forexample, in response to a certain angle of rotation, the controller maydisable columns 1012 and 1014. For each DMD 410 in the image projectionsystem 301, the controller refers to the table to determine how manycolumns or rows of mirrors should be disabled in each DMD.

Referring back to FIG. 9, at block 994, a first portion of the substrateis exposed to a first shot of electromagnetic radiation. Exposing thesubstrate may form a pattern on the substrate to expose a photoresist ofthe substrate. In one embodiment the image projection system 301 mayproduce the electromagnetic radiation. The electromagnetic radiation maybe visible light, for example, blue laser light emitted from the imageprojection system 301 and reflected off of the DMD 410. In oneembodiment, the image projection system 301 may expose a substrate anddeliver light to the surface of the substrate 140. Each exposure maylast between approximately about 45 microseconds and about 85microseconds, for example between about 55 microseconds and about 75microseconds.

Referring to FIG. 11, FIG. 11 illustrates areas of the substrate thatare exposed to a first shot of electromagnetic radiation. A substrategrid 1102 may be placed atop the substrate. The substrate grid 1102contains a plurality of equally spaced dots 1104. A DMD centroid grid1106 is superimposed with the substrate grid 1102. The DMD centroid grid1106 includes a plurality of equally spaced dots 1108. The substratesteps through the image projection system a predetermined step size. Thestep size is calculated by dividing the desired number of exposures bythe length of the DMD 410. Recall that at least one entire column ofmirrors was disabled in block 992. Therefore, the DMD length correspondsto the length of the DMD less the length of any columns that weredisabled in block 992. The vertical lines define one or more shapes 1110that are to be exposed. As the substrate moves through the imageprojection system one step size at a time, locations at which the dots1104 of the substrate grid overlap with the dots 1108 of the DMDcentroid grid 1106 within the shape 1110 are the locations at which thesubstrate will be exposed.

Referring back to FIG. 9, at block 996 the substrate is translated astep size and the second portion of the substrate is exposed to a secondshot of electromagnetic radiation. Similar to that described in FIG. 11,the substrate will be exposed at locations where the dots 1104 of thesubstrate grid 1102 overlap with the dots 1108 of the DMD centroid grid1106 within the shape 1110.

At block 998, the process of translating the substrate a step size andexposing a second portion to a second shot of electromagnetic radiationis repeated until the substrate is fully processed. Each exposure maygenerate a data set relating to graphical objects patterned on thesubstrate 140. Each data set may be stored in the memory 920 of thecontroller. Each data set may be combined to form the image pattern onthe substrate 140. Each exposure may form an aerial image of a portionof the substrate 140.

In another embodiment, a computer system for correcting non-uniformimage patterns on a substrate is disclosed. The computer system includesa processor and a memory. The memory stores instructions that, whenexecuted by the processor, cause the computer system to correct uniformimage patterns on a substrate. The steps include disabling at least oneentire column of mirrors in the DMD, wherein the DMD has a plurality ofcolumns each column having a plurality of mirrors, exposing a firstportion of the substrate to a first shot of electromagnetic radiation,translating the substrate a step size and exposing a second portion ofthe substrate to a second shot of electromagnetic radiation, andrepeating translating the substrate a step size and exposing a secondportion of the substrate to a second shot of electromagnetic radiationuntil the substrate is fully processed.

In yet another embodiment, a non-transitory computer-readable storagemedium, storing instructions that, when executed by the processor, causethe computer system to correct uniform image patterns on a substrate.The steps include disabling at least one entire column of mirrors in theDMD, wherein the DMD has a plurality of columns each column having aplurality of mirrors, exposing a first portion of the substrate to afirst shot of electromagnetic radiation, translating the substrate astep size and exposing a second portion of the substrate to a secondshot of electromagnetic radiation, and repeating translating thesubstrate a step size and exposing a second portion of the substrate toa second shot of electromagnetic radiation until the substrate is fullyprocessed.

Benefits of the embodiments disclosed herein may include the correctionof line edge roughness (“LER”) exposure defects through the use of asoftware setting. Undesirable line edge roughness may be created due tothe misalignment of the substrate on the stage or by vibration of thestage while the substrate is being processed thereon. Selectivelydisabling columns of mirrors of each DMD in response to the DMD's angleof rotation and number of desired shots may correct line edge roughnessexposure defects. Additionally, a DMD 410 may malfunction, causingexposure defects; however the utilization of the non-uniform patterncorrection application may fix a malfunction instantaneously via asoftware setting.

The application described herein maintains the ability to correctnon-uniform image patterns by selectively disabling columns of mirrorsin a DMD in response to the DMD's angle of rotation and desired numberof shots. The application exposes a first portion of the substrate to afirst shot of electromagnetic radiation, translates the substrate a stepsize, exposes a second portion of the substrate to a second shot ofelectromagnetic radiation.

While the foregoing is directed to embodiments described herein, otherand further embodiments may be devised without departing from the basicscope thereof. For example, aspects of the present disclosure may beimplemented in hardware or software or in a combination of hardware andsoftware. One embodiment described herein may be implemented as aprogram product for use with a computer system. The program(s) of theprogram product define functions of the embodiments (including themethods described herein) and can be contained on a variety ofcomputer-readable storage media. Illustrative computer-readable storagemedia include, but are not limited to: (i) non-writable storage media(for example, read-only memory devices within a computer such as CD-ROMdisks readable by a CD-ROM drive, flash memory, ROM chips or any type ofsolid-state non-volatile semiconductor memory) on which information ispermanently stored; and (ii) writable storage media (for example, floppydisks within a diskette drive or hard-disk drive or any type ofsolid-state random-access semiconductor memory) on which alterableinformation is stored. Such computer-readable storage media, whencarrying computer-readable instructions that direct the functions of thedisclosed embodiments, are embodiments of the present disclosure.

It will be appreciated to those skilled in the art that the precedingexamples are exemplary and not limiting. It is intended that allpermutations, enhancements, equivalents, and improvements thereto thatare apparent to those skilled in the art upon a reading of thespecification and a study of the drawings are included within the truespirit and scope of the present disclosure. It is therefore intendedthat the following appended claims include all such modifications,permutations, and equivalents as fall within the true spirit and scopeof these teachings.

What is claimed is:
 1. A method for correcting non-uniform imagepatterns on a substrate, comprising: in a digital micromirror device(DMD) installed in an image projection system, the DMD having aplurality of columns, each column having a plurality of mirrors,disabling at least one entire column of the plurality of columns;exposing a first portion of the substrate to a first shot ofelectromagnetic radiation; translating the substrate a step size andexposing a second portion of the substrate to a second shot ofelectromagnetic radiation; and iteratively translating the substrate astep size and exposing another portion of the substrate to another shotof electromagnetic radiation until the substrate has been completelyexposed to shots of electromagnetic radiation.
 2. The method of claim 1,wherein disabling columns of mirrors in a DMD installed in an imageprojection system comprises: searching a table having data regarding theangle of rotation of a DMD and a number of shots desired to determinethe number of columns of mirrors in the DMD to disable.
 3. The method ofclaim 1, wherein the step size is determined by dividing a number ofshots by a length of the DMD.
 4. The method of claim 1, wherein exposingforms a pattern on the substrate to expose a photoresist.
 5. The methodof claim 1, wherein each exposure generates a data set, wherein eachdata set is stored in a memory, and wherein each data set is combined toform an aggregate image on the substrate.
 6. The method of claim 1,wherein exposing a first portion of the substrate to a first shot ofelectromagnetic radiation comprises: exposing a portion of the substratein which DMD mirror centroids are located inside one or more shapes tobe exposed.
 7. The method of claim 1, wherein exposing is performed byat least one image projection.
 8. The method of claim 1, whereindisabling at least one entire column of mirrors in a DMD installed in animage projection system, wherein the DMD has a plurality of columns eachcolumn having a plurality of mirrors, comprises: measuring an angle ofrotation of a DMD installed in the image projection system; anddisabling at least one entire column of mirrors in the DMD responsive tothe measured angle of rotation.
 9. A computer system for correctingnon-uniform image patterns on a substrate, comprising: a processor; anda memory storing instructions that, when executed by the processor,cause the computer system to: (a) in a digital micromirror device (DMD)installed in an image projection system, the DMD having a plurality ofcolumns, each column having a plurality of mirrors, disable at least oneentire column of the plurality of columns; (b) expose a first portion ofthe substrate to a first shot of electromagnetic radiation; (c)translate the substrate a step size and exposing a second portion of thesubstrate to a second shot of electromagnetic radiation; and (d)iteratively translate the substrate a step size and expose anotherportion of the substrate to another shot of electromagnetic radiationuntil the substrate has been completely exposed to shots ofelectromagnetic radiation.
 10. The computer system of claim 9, whereindisabling columns of mirrors in a DMD installed in an image projectionsystem comprises: searching a table having data regarding the angle ofrotation of a DMD and a number of shots desired to determine the numberof columns of mirrors in the DMD to disable.
 11. The computer system ofclaim 9, wherein the step size is determined by dividing a number ofshots by a length of the DMD.
 12. The computer system of claim 9,wherein exposing forms a pattern on the substrate to expose aphotoresist.
 13. The computer system of claim 9, wherein each exposuregenerates a data set, wherein each data set is stored in a memory, andwherein each data set is combined to form an aggregate image on thesubstrate.
 14. The computer system of claim 9, exposing a first portionof the substrate to a first shot of electromagnetic radiation comprises:exposing a portion of the substrate in which DMD mirror centroids arelocated inside one or more shapes to be exposed.
 15. The computer systemof claim 9, wherein exposing is performed by at least one imageprojection.
 16. The computer system of claim 9, wherein disabling atleast one entire column of mirrors in a DMD installed in an imageprojection system comprises: measuring an angle of rotation of a DMDinstalled in the image projection system; and disabling at least oneentire column of mirrors in the DMD responsive to the measured angle ofrotation.
 17. A non-transitory computer-readable medium storinginstructions that, when executed by a processor, cause a computer systemto correct non-uniform image patterns on a substrate, by performing thesteps of: in a digital micromirror device (DMD) installed in an imageprojection system, the DMD having a plurality of columns, each columnhaving a plurality of mirrors, disabling at least one entire column ofthe plurality of columns; exposing a first portion of the substrate to afirst shot of electromagnetic radiation; translating the substrate astep size and exposing a second portion of the substrate to a secondshot of electromagnetic radiation; and iteratively translating thesubstrate a step size and exposing another portion of the substrate toanother shot of electromagnetic radiation until the substrate has beencompletely exposed to shots of electromagnetic radiation.
 18. Thenon-transitory computer-readable medium of claim 17, wherein disablingcolumns of mirrors in the DMD comprises: searching a table having dataregarding the angle of rotation of a DMD and a number of shots desiredto determine the number of columns of mirrors in the DMD to disable. 19.The non-transitory computer-readable medium of claim 17, wherein thestep size is determined by dividing a number of shots by a length of theDMD.
 20. The non-transitory computer-readable medium of claim 17,exposing a first portion of the substrate to a first shot ofelectromagnetic radiation comprises: exposing a portion of the substratein which DMD mirror centroids are located inside one or more shapes tobe exposed.